Patents by Inventor Tatsushi Shimizu
Tatsushi Shimizu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20080313882Abstract: In a sensing unit according to the present invention, a spring portion having a support portion and a movable portion is conductive. A signal of a sensor portion provided on the movable portion of the spring portion is transmitted via the spring portion. Hence, the sensing unit according to the present invention has a simple constitution with a small number of components, and a wire does not necessarily have to be provided for each sensor portion. As a result, a reduction in manufacturing cost, simplification of the manufacturing process, and so on are achieved.Type: ApplicationFiled: June 20, 2007Publication date: December 25, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Tatsushi Shimizu, Takehiro Horinaka, Kazuo Ishizaki, Shigeki Tanemura
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Patent number: 7463448Abstract: The present invention is directed to a thin-film magnetic head having no ATE (adjacent track erase) problem, a very narrow track width, an excellent O/W (overwrite) characteristic and a high switching speed. A lower pole film of a write element is provided on one face of a lower yoke film inside a trench portion provided in an inorganic insulating film. A gap film and an upper pole film are provided inside the trench portion on the lower pole portion. The trench portion has preferably an attached film made of an inorganic material on the inner wall faces facing the side faces of said lower pole film, said gap film and said upper pole film.Type: GrantFiled: April 20, 2005Date of Patent: December 9, 2008Assignees: Headway Technologies, Inc., SAE Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Takehiro Kamigama, Tatsushi Shimizu
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Patent number: 7463450Abstract: A thin film magnetic head has a configuration in which a main magnetic pole film having a magnetic pole end portion on a medium opposing surface (ABS) side facing a magnetic disk, a write shield film facing the magnetic pole end portion so as to form a recording gap film on the medium opposing surface side, and a thin film coil wound around at least a part of the write shield film are laminated. Further, the thin film magnetic head has an upper yoke magnetic pole film whose size is larger than that of the main magnetic pole film at a part more distant from the ABS than the recording gap film, and this upper yoke magnetic pole film is bonded to the side of the main magnetic pole film close to the thin film coil. In the upper yoke magnetic pole film, an end portion on the ABS side is retracted in a direction apart from the ABS in accordance with an increase in film thickness which is measured from the surface of the main magnetic pole film.Type: GrantFiled: May 23, 2005Date of Patent: December 9, 2008Assignees: Headweay Technologies, Inc., Sae Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Takehiro Kamigama, Tatsushi Shimizu
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Publication number: 20080295328Abstract: In a method of manufacturing an electronic component package, first, a plurality of sets of external connecting terminals corresponding to a plurality of electronic component packages are formed by plating on a top surface of a substrate to thereby fabricate a wafer. The wafer includes a plurality of pre-base portions that will be separated from one another later to become bases of the respective electronic component packages. Next, at least one electronic component chip is bonded to each of the pre-base portions of the wafer. Next, electrodes of the electronic component chip are connected to the external connecting terminals. Next, the electronic component chip is sealed. Next, the wafer is cut so that the pre-base portions are separated from one another and the plurality of bases are thereby formed.Type: ApplicationFiled: May 29, 2007Publication date: December 4, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Tatsushi Shimizu
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Patent number: 7417442Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.Type: GrantFiled: May 17, 2005Date of Patent: August 26, 2008Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.Inventors: Nozomu Hachisuka, Kenji Inage, Norio Takahashi, Tatsushi Shimizu, Pak Kin Wong
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Publication number: 20080197484Abstract: In a method of manufacturing an electronic component package, first, there is fabricated a wafer incorporating a plurality of sets of external connecting terminals corresponding to a plurality of electronic component packages, and a retainer for retaining the plurality of sets of external connecting terminals, the wafer including a plurality of pre-base portions that will be separated from one another later to be bases of the electronic component packages. Next, at least one electronic component chip is bonded to each of the pre-base portions of the wafer. Next, electrodes of the electronic component chips are connected to the external connecting terminals. Next, the electronic component chips are sealed. Next, the wafer is cut so that the pre-base portions are separated from one another and the plurality of bases are thereby formed.Type: ApplicationFiled: February 15, 2007Publication date: August 21, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Tatsushi Shimizu
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Publication number: 20080184551Abstract: Components of a plurality of magnetic heads are formed on a single substrate to fabricate a magnetic head substructure in which a plurality of pre-head portions are aligned in a plurality of rows. The substructure is cut to separate the plurality of pre-head portions from one another, and the plurality of magnetic heads are thereby fabricated. The surface formed by cutting the substructure is lapped to form a lapped surface. The lapped surface is lapped so as to reach a target position of a medium facing surface. The substructure incorporates first to fourth resistor elements each of which detects the position of the lapped surface. The third and fourth detection elements are located at positions shifted from the first and second resistor elements along the direction orthogonal to the medium facing surface.Type: ApplicationFiled: February 5, 2007Publication date: August 7, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Kazuo Ishizaki, Ryuji Fujii, Tatsushi Shimizu
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Patent number: 7408740Abstract: A thin-film magnetic head for perpendicular magnetic recording according to the present invention comprises a coil to generate a magnetic field, and a main pole layer to perform the perpendicular recording using the magnetic field generated by said coil. The lower surface as to the layer-forming direction of said main pole layer has irregularities at the medium-facing surface side end.Type: GrantFiled: April 21, 2005Date of Patent: August 5, 2008Assignees: Headway Technologies, Inc., SAE Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Takehiro Kamigama, Tatsushi Shimizu
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Patent number: 7365942Abstract: A thin-film magnetic head for perpendicular magnetic recording comprises a coil, a main magnetic pole layer for performing perpendicular recording, a write shield layer and a write gap layer, wherein the main magnetic pole layer comprises a main pole film portion and a yoke pole film portion. The write shield layer has a first shield film portion for determining a throat height, and the thickness of the first shield layer is smaller than the thickness of the yoke pole film portion.Type: GrantFiled: June 22, 2005Date of Patent: April 29, 2008Assignees: Headway Technologies, Inc., SAE Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Takehiro Kamigama, Tatsushi Shimizu
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Publication number: 20080094059Abstract: A magnetic film sensor comprises a magnetic film for generating a magnetostriction, and a magnetostrictive structure for generating a magnetostriction in the magnetic film. The magnetostrictive structure is constructed so as to generate a magnetostriction by curving the magnetic film, for example. The magnetostrictive structure is obtained, for example, by providing a depressed insulating layer having a surface formed with a depression and forming the magnetic film across the depression.Type: ApplicationFiled: October 24, 2006Publication date: April 24, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K) LTD., KOJI SHIMAZAWAInventors: Yoshitaka Sasaki, Koji Shimazawa, Tatsushi Shimizu
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Publication number: 20080088972Abstract: A magnetic head comprises a pole layer, a first coil, a second coil, and a shield. The shield incorporates: a first portion located backward of the pole layer along the direction of travel of a recording medium; a second portion located forward of the pole layer along the direction of travel of the recording medium; and two coupling portions. The first portion has an end face located in a medium facing surface. The two coupling portions couple the first and second portions to each other without touching the pole layer. Part of the first coil passes through a space surrounded by the pole layer and the first portion. Part of the second coil passes through a space surrounded by the pole layer and the second portion.Type: ApplicationFiled: October 13, 2006Publication date: April 17, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Shigeki Tanemura, Tatsushi Shimizu, Tatsuya Shimizu
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Publication number: 20080088971Abstract: A magnetic layer for writing incorporates: a pole layer having an end face located in a medium facing surface; and an upper yoke layer. A first magnetic layer for flux concentration is connected to the pole layer at a location away from the medium facing surface, and allows a magnetic flux corresponding to a magnetic field generated by a first coil to pass. A second magnetic layer for flux concentration is connected to the upper yoke layer at a location away from the medium facing surface, and allows a magnetic flux corresponding to a magnetic field generated by a second coil to pass. When seen in the direction orthogonal to the interface between the second magnetic layer and the upper yoke layer, this interface is disposed at a location that does not coincide with the interface between the first magnetic layer and the pole layer.Type: ApplicationFiled: October 13, 2006Publication date: April 17, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Shigeki Tanemura, Tatsushi Shimizu, Tatsuya Shimizu
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Publication number: 20080068747Abstract: A magnetic head comprises: an encasing layer having a groove; a nonmagnetic metal layer that has a sidewall located directly above the edge of the groove and that is disposed on a region of the encasing layer away from the medium facing surface; two side shield layers that have sidewalls located directly above the edge of the groove and that are disposed adjacent to the nonmagnetic metal layer on regions of the encasing layer closer to the medium facing surface than the nonmagnetic metal layer; and a pole layer. The pole layer is placed in an encasing section formed of the groove of the encasing layer, the sidewall of the nonmagentic metal layer, and the sidewalls of the two side shield layers. The two side shield layers have end faces located in the medium facing surface on both sides of the end face of the pole layer, the sides being opposed to each other in the direction of track width.Type: ApplicationFiled: September 11, 2006Publication date: March 20, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Takehiro Horinaka, Hironori Araki, Tatsushi Shimizu, Tatsuya Shimizu
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Publication number: 20080024911Abstract: A shield incorporates: a first layer, a second layer, a third layer, a first coupling portion, and a second coupling portion. The first layer has: a first surface located in a region of a medium facing surface forward of an end face of a pole layer along the direction of travel of a recording medium; a second surface opposed to the pole layer; and a third surface opposite to the second surface. The second layer touches the third surface. The third layer is disposed in a region sandwiching the pole layer with the first layer. The first coupling portion couples the first layer to the third layer without touching the pole layer. The second coupling portion is located farther from the medium facing surface than the first coupling portion and couples the pole layer to the third layer.Type: ApplicationFiled: July 26, 2006Publication date: January 31, 2008Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Tatsushi Shimizu, Tatsuya Shimizu
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Publication number: 20080013209Abstract: A magnetic head comprises a pole layer, a shield layer, a gap layer disposed between the pole layer and the shield layer, and a coil. The shield layer incorporates a first layer, a second layer, a third layer and a fourth layer that are disposed on the gap layer one by one. The first layer has an end face located in a medium facing surface. The second layer has: a first surface located in the medium facing surface; a second surface touching the first layer; and a third surface opposite to the second surface. The third layer touches the third surface of the second layer. An end face of each of the third and fourth layers closer to the medium facing surface is located at a distance from the medium facing surface.Type: ApplicationFiled: July 12, 2006Publication date: January 17, 2008Applicants: Headway Technologies, Inc., SAE Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Shigeki Tanemura, Hironori Araki, Dong-Hong Li, Tatsushi Shimizu, Tatsuya Shimizu
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Publication number: 20080007871Abstract: The head slider has a plurality of heaters each heating a corresponding region of the ABS, and a sensor detecting collision of the ABS with a projection on a surface of the magnetic disk. Currents supplied to the respective heaters are controlled and produce heats independently of one another. The heats produce projections on the corresponding regions of the ABS, respectively. The ABS with asperity can be planarized through appropriately controlling magnitude of the currents supplied to the heaters. Thus, the variation of a sensor output depending on asperity of the ABS is effectively reduced. Another head slider has a heater locally heating a corresponding region of the ABS. The heater has a structure where a central portion is away from the ABS compared with end portions, or a structure where calorific power of a central portion is smaller than that of each of end portions. Thus, overall projection shape becomes flat.Type: ApplicationFiled: June 25, 2007Publication date: January 10, 2008Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.Inventors: Hiroshi Kiyono, Nobuya Oyama, Katsuki Kurihara, Noboru Yamanaka, Chung Keung Ho, Cheung Kwan Lau, Tatsushi Shimizu
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Publication number: 20080002293Abstract: A thin-film magnetic head is manufactured as follows. First, a base insulating layer having a magnetic pole forming depression sunken into a form corresponding to the main magnetic pole layer is formed, a stop film for CMP is formed such as to fill the magnetic pole forming depression, and then a magnetic layer is formed on the stop film. Next, the magnetic layer is separated by forming a separation groove substantially surrounding the magnetic pole forming depression on the outside thereof, and thus separated magnetic layer is formed with a cover insulating film adapted to cover the whole upper face. The surface is polished by CMP until the stop film is exposed, so that the part of magnetic layer remaining on the inside of the magnetic pole forming depression is used as the main magnetic pole layer. Further, a recording gap layer, a write shield layer, and a thin-film coil are formed.Type: ApplicationFiled: April 19, 2006Publication date: January 3, 2008Applicants: Headway Technologies Inc., SAE Magnetics (H.K.) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Takehiro Horinaka, Takehiro Kamigama, Tatsushi Shimizu
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Publication number: 20070014048Abstract: A method of manufacturing a thin-film magnetic head structure comprises the steps of preparing an insulating layer 10; forming a first resist layer 51 provided with a first slit pattern 51a corresponding to a very narrow groove part and a second slit pattern 51b corresponding to a temporary groove part integrally extending from the very narrow groove part along outer edges of a main depression onto the insulating layer 10; etching the insulating layer 10 while using the first resist layer 51 as a mask; eliminating the first resist layer 51; forming a second resist layer having an opening pattern corresponding to the main depression onto the insulating layer 10; and etching the insulating layer 10 while using the second resist layer as a mask.Type: ApplicationFiled: July 13, 2005Publication date: January 18, 2007Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.) LTD.Inventors: Yoshitaka Sasaki, Hiroyuki Ito, Takehiro Kamigama, Tatsushi Shimizu, Hironori Araki, Shigeki Tanemura, Kazuo Ishizaki
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Publication number: 20060291096Abstract: A thin-film magnetic head for perpendicular magnetic recording comprises a coil, a main magnetic pole layer for performing perpendicular recording, a write shield layer and a write gap layer, wherein the main magnetic pole layer comprises a main pole film portion and a yoke pole film portion. The write shield layer has a first shield film portion for determining a throat height, and the thickness of the first shield layer is smaller than the thickness of the yoke pole film portion.Type: ApplicationFiled: June 22, 2005Publication date: December 28, 2006Applicants: Headway Technologies, Inc., SAE Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Takehiro Kamigama, Tatsushi Shimizu
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Publication number: 20060262440Abstract: A thin film magnetic head has a configuration in which a main magnetic pole film having a magnetic pole end portion on a medium opposing surface (ABS) side facing a magnetic disk, a write shield film facing the magnetic pole end portion so as to form a recording gap film on the medium opposing surface side, and a thin film coil wound around at least a part of the write shield film are laminated. Further, the thin film magnetic head has an upper yoke magnetic pole film whose size is larger than that of the main magnetic pole film at a part more distant from the ABS than the recording gap film, and this upper yoke magnetic pole film is bonded to the side of the main magnetic pole film close to the thin film coil. In the upper yoke magnetic pole film, an end portion on the ABS side is retracted in a direction apart from the ABS in accordance with an increase in film thickness which is measured from the surface of the main magnetic pole film.Type: ApplicationFiled: May 23, 2005Publication date: November 23, 2006Applicants: Headway Technologies, Inc., SAE Magnetics (H.K.) Ltd.Inventors: Yoshitaka Sasaki, Hiroyuki Itoh, Takehiro Kamigama, Tatsushi Shimizu